Polysaccharide-based fluids such as guar fluids are commonly used in hydraulic fracturing operations, primarily because of their abundance, relative low cost, and capability to work at up to 350° F. when formulated at high pH (for example, greater than 9.5). One notable disadvantage, however, for most guar-based fracturing fluids is the insoluble residue in guar which tends to cause permeability reduction. Another disadvantage for using guar-based fluids at high pH is the tendency for forming divalent ion scales at high pH. In general, thermally stable synthetic polymers, such as acrylamide based polymers are considered to be residue-free. These polymers can be used for preparing fracturing fluids around 300-450° F. or more. However, a high dosage of acrylamide based polymers may still cause formation damage due to factors such as incomplete degradation.